Coronally advanced flap combined with Geistlich Mucograft for the treatment of recession type defects: a randomized controlled clinical trial.

The main indications for root coverage procedures are esthetic / cosmetic
demands, root sensitivity as well as changing the topography of the marginal
soft tissue to facilitate plaque control (Wennström, et al. 2008).
The coronally advanced flap (CAF) combined with a free connective tissue graft
(FCTG) is considered the *gold standard* for root coverage therapy.
Consequently, alternative root coverage techniques are generally compared to
CAF + FCTG and evaluated according to their ability to reduce recession and
achieve root coverage (Oates, et al. 2003, Academy-Report 2005, Chambrone, et
al. 2009). Moreover CAF + FCTG can be used for root coverage of a single tooth
as well as multiple teeth, provided suitable donor tissue is available
(Wennström, et al. 2008). However, especially the procedure to gain a FCTG from
the area of the masticatory mucosa in the palate is rather technically
demanding. Furthermore, the need for a second surgical site to harvest the
graft tissue and resulted morbidity acts as limiting factors for this
technique. Moreover, the donor tissue from the palatal region may be
insufficient for multiple recession treatments.
To overcome these drawbacks a xenogenic collagen matrix (CM; Mucograft®
Collagen Matrix, Geistlich Pharma Ag, Wolhusen, Switzerland) has been
developed. Recently, CAF + CM in comparison with a CAF + FCTG has been used in
a randomized controlled clinical trial (RCT) (McGuire and Scheyer 2010).
McGuire and Scheyer (McGuire and Scheyer 2010) report that the residual
recession depth at 6 and 12 months after surgery was significantly less for CAF
+ FCTG (after 6 months: p < 0.01, after 12 months: p < 0.05). Furthermore,
percentage root coverage (RC) at 6 and 12 months after surgery was
significantly more for CAF + FCTG (after 6 months: p < 0.01, after 12 months: p
< 0.05). However, if only maxillary cases were considered (N=20) CAF+CM - and
CAF+FCTG results were more nearly matched and became statistically
indistinguishable at 1 year (91.1 ± 19.6% RC for CAF+CM and 99.2 ± 3.6% RC for
CAF+FCTG; p=0.125). Similarly, when four problematic subjects were excluded
from the overall study results - two graft trauma subjects, one methotrexate
prescribed subject and one oncology radiation subject - overall RC draw even
closer together (93.3 ± 14.7% RC for CAF+CM and 99.2 ± 3.7% RC for CAF+FCTG)
and were, again, statistically indistinguishable at 1 year (p=0.125).
Nonetheless, the variance for percentage root coverage in the CAF + CM group
was still increased compared to the CAF + FCTG group. Moreover, as 95%
confidence intervals for the mean recession depths and recession depth change
were not provided, the transferability of the results is not clear.
Most recently, Cardaropoli et al. (Cardaropoli, et al. 2011) compared CAF+CM
with CAF+FCTG in a RCT. In contrast to McGuire and Scheyer (McGuire and Scheyer
2010), Cardaropoli et al. (Cardaropoli, et al. 2011) report that residual
recession depth (rRD) as well as percentage of RC at 12 months after surgery
were not significantly different for CAF+CM as compared with CAF + FCTG (0.23 ±
0.47 mm rRD for CAF+CM and 0.09 ± 0.20 mm rRD for CAF+FCTG; 96.97 ± 6.74% RC
for CAF+CM and 94.32 ± 11.68% RC for CAF+FCTG ; p > 0.05 using a paired t-test
with 80% power and 0.05 level of significance). Finally, Cardaropoli et al.
(Cardaropoli, et al. 2011) conclude that for CAF+CM recession reduction and
percentage of root coverage are similar to those achieved by the use of
CAF+FCTG.
Obviously, the currently available results for CAF+CM are not uniform.
Therefore, in order to get more insight in patient and surgical site selection
criteria the present study proposal aims to investigate CAF + CM compared to
CAF + FCTG for single or multiple maxillary Miller class I and II recession
defects (Miller 1985) in healthy patients.

As stated before, the aim of this study is to investigate CAF + CM compared to
CAF + FCTG for single or multiple maxillary Miller class I and II recession
defects in healthy patients. In this way we can get more insight in patient and
surgical site selection criteria.

This study is a RCT.

Enrollment in the study
Assessment of:
-FMPS (Full Mouth Plaque Score)
-FMBS (Full Mouth Bleeding Score)
-PPD (Probing Pocket Depth)
-PAL (Probing Attachment Level)
-RECd (Recession depth of the gingival margin)
-RECw (Recession width of the dehiscence defect)
-KTw (Keratinized Tissue width)
-DP (Digital Picture) to calculate percentage of defect coverage with digital
image analysis software
-Radiograph (in order to classify the recession type defects according to
Miller (Miller 1985)

Surgery (Baseline, BL)
Assessment of:
-FMPS
-FMBS
-PPD
-PAL
-RECd
-RECw
-KTw
-DP

At 6, 12, and 24 months after BL
Assessment of:
-FMPS
-FMBS
-PPD
-PAL
-RECd
-RECw
-KTw
-DP

Patients can be asked to come again for a clinical examination at 1 and/or 2
year(s) after BL.

Six, 12, and 24 months after surgery, a participant will have to visit a
dentist of our department for clinical measurements and a digital picture.
Patients might be asked to visit the dentist again 3 and/or 5 years after
surgery for the same clinical measurements. Because the clinical examination
will not take very much time (0,5-1 hour) and the measurements are
non-invasive, the burden associated with participation is not big.
As stated before, the collagen matrix (Geistlich Mucograft) used in the test
group is a registered and approved product that has been used in general dental
practice for some time. Therefore, there is no risk using this material in
patients.