Treatment of Localized Gingival Recession Defects at Lower Mandibular Incisors Using a Modified-free Gingival Graft: a Randomized Clinical Trial
Phase: NA
Conditions: Gingival Recession, Localized
Sponsor: Göteborg University

 
 
 
 
 
 
 
 
 
10 December 2020 
 
 
 
 
 
 
Research protocol  
 
 
Effectiveness of Modified-free Gingival Graft for 
Treatment of Localized Gingival Recession 
Defects    
 
NCT04718545 
 
 
 
 
 
Principal investigator: 
Olivier Carcuac, DDS, PhD 
 
The Sahlgrenska Academy at University of Gothenburg 
 
Institute of Odontology 
 
Department of Periodontology 
 
Box 450 
 
SE 405 30 Gothenburg 
 
Sweden 
 
Email:   olivier.carcuac@odontologi.gu.se 
 
 
 
 

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Objectives 
 
The aim of the present study is to evaluate, whether use of the modified free 
gingival graft (mod-FGG) technique improves treatment outcomes after surgical 
root coverage at mandibular incisors with gingival recession defects. 
 
Background 
 
Gingival recession defects (GRD), defined as displacement of the gingival margin 
apical to the cemento–enamel junction (CEJ) (1), are frequent clinical findings in the 
general population (2). According to Albandar et al. (3), who examined almost 
10,000 adult subjects (aged 30-90 years) in the United States, gingival recessions (≥1 
mm) were most prevalent at maxillary first molars and mandibular central incisors, 
noted in 35% of all individuals. 
Indications for root coverage procedures include improved esthetics, reduction of 
root hypersensitivity and increase of the dimensions of keratinized tissue in order 
to facilitate infection control and prevent further progression of GRD. Numerous 
surgical techniques for root coverage have been suggested, with different degrees of 
success as assessed by the proportion of complete root coverage (CRC) (4,5). The 
influence of anatomical factors, such as a shallow vestibule, root prominence and 
limited width of keratinized tissue on treatment outcomes has been highlighted 
(6,7). Moreover, Zucchelli and coworkers (8) demonstrated that tooth location is 
crucial in predicting the level of final root coverage. The authors noted the least 
favourable outcomes at mandibular incisors. The lower success rate and lower 
predictability of root coverage at lower incisors, teeth with a high frequency of 
GRDs (3), may be explained by unfavorable anatomic conditions including 
marginal frenum attachment, high muscle pull and a shallow vestibule. These 
features are frequently encountered in the anterior area of the mandible, while they 
are rare in the maxillary anterior region (9). 
Different surgical procedures aiming at root coverage have been described in the 
literature (11). Thus, coronally and laterally displaced flaps may be used alone or in 
combination with connective tissue grafts. Tunneling techniques were suggested, 
minimizing the need for surgical incisions (13). The free gingival graft (FGG) 
represents a different approach that includes the harvesting of connective and 
epithelial tissues (15). FGG was shown to be the most effective procedure for 

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gingival augmentation at sites with minimal amount of keratinized tissue (10), but 
was initially suggested to be used for root coverage (14-17). Great variability in 
terms of proportion of root coverage (range: 11% to 87%; mean: 63%) has been 
reported when applying this technique, however (12). One of the challenges may be 
the inadequate blood supply to the portion of the FGG placed on the exposed root 
surface. It is currently not understood, whether the blood supply to the FGG and, 
ultimately, treatment outcomes can be improved by modifying the surgical 
technique (mod-FGG). 
 
Study design 
Aim 
The purpose of this randomized control trial is to compare clinical outcomes of 
surgical root coverage using either FGG or mod-FGG in the treatment of localized 
RT1 gingival recession defects at lower incisors. 
 
Subjects and sample size 
30 patients with localized gingival recession defects (RT1) at mandibular incisor 
will be included and randomly allocated to 2 treatment groups: a control group that 
will be treated with the conventional FGG technique and a test group that will be 
treated with the mod-FGG approach. 
Inclusion criteria 
Subjects with at ≥1 buccal RT1 gingival recession defect (18, 19, 20) at mandibular 
incisor will be invited considering the following inclusion criteria: 
• 
age ≥18 years 
• 
good general health 
• 
non-smoker 
• 
periodontally healthy 
• 
low full-mouth plaque score 
• 
thin phenotype 
 
The tooth/teeth to be treated shall present with: 

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• 
probing pocket depth (PPD) ≤3 mm 
• 
absence of excessive tooth mobility 
• 
absence of cervical composite restorations or non-carious cervical lesions 
• 
a shallow vestibule 
 
Exclusion criteria 
A subject meeting any of the following criteria will no be considered for inclusion: 
• pregnancy 
• smoking 
• alcoholism 
• para-functional habits 
• poor oral hygiene 
• excessive crowding or misalignment of teeth 
 
Protocol 
 
Randomization  
Patients will be randomized to one of the two treatment groups with the use of a 
computer-generated table (ratio 1:1). Allocation will be concealed until the time of 
surgery. 
 
Initial therapy, clinical measurements and patient-reported outcomes 
Following an initial screening examination, all subjects will receive a session of 
prophylaxis including instructions in proper oral hygiene measures, scaling and 
professional tooth cleaning with the use of a rubber cup and a low abrasive 
polishing paste. Surgical treatment of the recession defects will not be scheduled 
until patients have demonstrated adequate standards of supragingival plaque 
control.  
 
The following clinical measurements will be obtained 1 week prior to the surgical 
intervention and at the 1 year follow up-visit:  
- gingival recession depth (RD): measured from the CEJ to the most apical extension 
of the soft-tissue margin 

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- probing depth (PD): measured from the soft- tissue margin to the bottom of the 
sulcus 
- clinical attachment level (CAL): measured from the CEJ to the bottom of the 
sulcus.  
- keratinized tissue height (KTH): measured from the soft- tissue margin to the 
mucogingival junction identifiable with Lugol® (J.Crow Company, New Ipswich, 
NH, USA) staining.  
 
All measurements will be performed at the mid facial aspect of the treated teeth by 
means of a manual periodontal probe (PCP15, Hu-Friedy, Chicago, IL, USA) and 
will be rounded to the nearest millimeter. Measurements will be performed by a 
single examiner (OC). Full mouth plaque (FMPS) and bleeding (FMBS) scores will 
also be recorded using the percentage of total positive surfaces (four aspects per 
tooth). 
Hypersensitivity and post-operative discomfort will be assessed through a visual 
analogue scale. The intake of pain medication and post-surgical swelling will also 
be recorded. 
 
Root coverage procedures 
All interventions will be performed by one experienced periodontist (OC). 
Mechanical instrumentation of root surfaces will be performed prior to surgery.  
 
Test group - modified free gingival graft 
The modified free gingival graft (mod-FGG) technique proposed by Carcuac & 
Derks (21) will be applied at test sites. The following steps will be included: 
 
1 - Preparation of the recipient site: Initially, an intrasulcular incision will be made 
along the exposed root surface followed by 2 mm long horizontal incisions placed 
at the level of the CEJ. From each horizontal incision, vertical releasing incisions 
will then be placed in a diverging manner, extending well into the alveolar mucosa. 
A thin partial thickness flap will be created and excised, thereby delimiting the 
recipient area. The dimension of the recipient site will be accurately measured and 
reported on a foil template. 
 
2 - Preparation of the connective tissue pedicle flap: 

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Apically to the recession defect, at a distance corresponding to the height of the 
exposed root surface, one horizontal incision and two vertical and slightly 
diverging, coronally directed incisions will be performed, delimiting the connective 
tissue pedicle flap. The flap will then be carefully dissected from the periosteum in 
a coronal direction. No dissection will be performed in the region directly apical to 
root surface, leaving the flap attach at its most coronal aspect. The connective tissue 
pedicle graft will then be flipped coronally and anchored on the exposed root 
surface through laterally placed bioabsorbable sutures. 
 
3 - Harvesting of the free gingival graft: 
The graft dimensions will be outlined in the palate adjacent to the premolars and 
first molar using the foil template created to match the recipient bed. A partial 
thickness graft consisting of epithelium and a thin layer of underlying connective 
tissue will be harvested, maintaining a distance of ≥2 mm to the maxillary teeth. 
The thickness of the graft will be about 1.5 mm. Following harvesting of the FGG, 
several drops of high-viscosity cyanoacrylate tissue adhesive will be applied to the 
palatal wound before covering it with a porcine-derived collagen sponge. The 
sponge will be stabilized by crossed sutures. 
 
4 - Placement of the graft: 
The FGG will be adapted to the recipient site and anchored to the periosteum by 
means of simple interrupted sutures using a 6/0 non-resorbable monofilament. 
Suturing will be continued along the lateral borders of the graft until complete 
stability of the graft is achieved. Vertically suspended crossed sutures will be 
placed, when needed, to achieve a slight compression of the graft to the recipient 
site. 
 
Control group - traditional free gingival graft 
The same surgical approach as outline for the test group with the exception of the 
connective tissue pedicle flap will be performed at control sites. 
 
Data Analysis 
Statistical analysis 
Continuous data will be expressed as mean ±SD. Student’s t-test will be used to 
evaluate changes of RD, PD, CAL and KTH as well as patient reported measures of 

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discomfort in test and control groups. Pearson’s chi-square test will be used to 
compare CRC (categorical data). Regression analysis will be used to evaluate the 
correlation between reduction of RD to baseline RD and other potential 
confounding factors.  
 
Sample size 
The proposed sample size of 2x15 subjects has a power of 80% (alpha: 0.05; beta: 
0.2) to detect a difference of the rate of CRC from 48% to 88% (22). 
 
Ethical Requirements 
The study protocol will be evaluated by the regional ethical board. All patients will 
be given information about the study design and their right to withdraw from the 
study at any time without negatively affecting their future treatment. Informed 
consent will be obtained from each patient willing to participate. 
 
Study outline 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2 weeks – SUTURE REMOVAL 
              - Professional cleaning 
Initial Examination 
- RD, PD, CAL, KTH 
- patient recruitment 
- randomization 
        TEST GROUP 
Mod-FGG 
CONTROL GROUP 
FGG 
                   SURGERY 
                   SURGERY 
2 weeks – SUTURE REMOVAL 
               - Professional cleaning 
1, 3, 6 months 
- Professional cleaning 
- OH re-inforcement 
1, 3, 6 months 
- Professional cleaning 
- OH re-inforcement 
1 year 
- Re-examination 
 1 year 
- Re-examination 

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References 
 
1. American Academy of Periodontology. Consensus report on mucogingival 
therapy. Proceedings of the World Workshop in Periodontics. Ann 
Periodontol 1996: 1: 702–706. 
 
2. Serino G, Wennström JL, Lindhe J, Eneroth L. The prevalence and 
distribution of gingival recession in subjects with a high standard of oral 
hygiene. J Clin Periodontol 1994: 21: 57–63. 
 
3. Albandar JM, Kingman A. Gingival recession, gingival bleeding, and dental 
calculus in adults 30 years of age and older in the United States, 1988-1994. J 
Periodontol. 1999;70(1):30-43. 
 
4. Cairo F, Nieri M, Pagliaro U (2014). Efficacy of periodontal plastic surgery 
procedures in the treatment of localized facial gingival recessions. A 
systematic review. 41 Suppl 15:S44–62 
 
5. Graziani F, Gennai S, Roldán S, Discepoli N, Buti J, Madianos P, et al. (2014). 
Efficacy of periodontal plastic procedures in the treatment of multiple 
gingival recessions. 41 Suppl 15:S63–76 
 
6. Huang LH, Neiva RE, Wang HL. Factors affecting the outcomes of coronally 
advanced flap root coverage procedure. J Periodontol. 2005;76:1729-1734 
 
7. Aroca S, Barbieri A, Clementini M, Renouard F, de Sanctis M. Treatment of 
class III multiple gingival recessions: prognostic factors for achieving a 
complete root coverage. J Clin Periodontol. 2018;45:861-868. 
 
8. Zucchelli G, Tavelli L, Barootchi S, Stefanini M, Rasperini G, Valles C, et al. 
(2019). The influence of tooth location on the outcomes of multiple adjacent 
gingival recessions treated with coronally advanced flap: A multicenter re-
analysis study. J Periodontol 90:1244–1251. 
 
9. Zucchelli G, Tavelli L, Ravida A, Stefanini M, Suarez- Lopez Del Amo F, 
Wang HL. Influence of tooth location on coronally advanced flap procedures 
for root coverage. J Periodontol. 2018;89(12):1428-1441. 
 
10. Tonetti MS, Jepsen S, Working Group 2 of the European Workshop on 
Periodontology. Clinical efficacy of periodontal plastic surgery procedures: 
consensus report of Group 2 of the 10th European Workshop on 
Periodontology. J Clin Periodontol 2014: 41(Suppl 15): S36– S43. 
 
11. Cairo F (2017). Periodontal plastic surgery of gingival recessions at single 
and multiple teeth. Periodontol 2000 75:296–316. 
 
12. Wennström JL. Mucogingival therapy. Ann Periodontol 1996: 1: 671–701. 
 
13. Zabalegui I, Sicilia A, Cambra J, Gil J, Sanz M. Treatment of multiple 
adjacent gingival recessions with the tunnel subepithelial connective tissue 
graft: a clinical report. Int J Periodontics Restorative Dent 1999: 19: 199–206. 

9 
 
 
 
 
14. Miller PD Jr. Root coverage with the free gingival graft. Factors associated 
with incomplete coverage. J Periodontol. 1987;58(10):674-681. 
15. Bjorn H. Free transplantation of gingiva propria. Sven Tandlak Tidskr. 
1963;22:684–689. 
16. Nabers JM. Free gingival grafts. Periodontics. 1966;4(5):243-245. 
17. Holbrook T, Ochsenbein C. Complete coverage of the denuded root surface 
with a one-stage gingival graft. Int J Periodontics Restorative Dent. 
1983;3(3):8-27. 
18. Cairo F, Nieri M, Cincinelli S, Mervelt J, Pagliaro U. The interproximal 
clinical attachment level to classify gingival recessions and predict root 
coverage outcomes: an explorative and reliability study. J Clin Periodontol. 
2011;38(7):661-666. 
19. Cortellini P, Bissada NF. Mucogingival conditions in the natural dentition: 
Narrative review, case definitions, and diagnostic considerations. J 
Periodontol. 2018;89 Suppl 1:S204-S213. 
 
20. Jepsen S, Caton JG, Albandar JM, et al. Periodontal manifestations of 
systemic diseases and developmental and acquired conditions: Consensus 
report of workgroup 3 of the 2017 World Workshop on the Classification of 
Periodontal and Peri-Implant Diseases and Conditions. J Clin Periodontol. 
2018;45 Suppl 20:S219-S229. 
 
21. Carcuac O, Derks J. Modified free-gingival graft procedure for root coverage 
in the anterior mandible. Accepted for publication in Int J Periodontics 
Restorative Dent. 
 
22. Zucchelli G, Marzadori M, Mounssif I, Mazzotti C, Stefanini M. Coronally 
advanced flap + connective tissue graft techniques for the treatment of deep 
gingival recession in the lower incisors. A controlled randomized clinical 
trial. J Clin Periodontol. 2014;41(8):806-813.