ORIGINAL ARTICLE

Dimensional changes in free gingival grafts: scalpelversus Er:YAG laser—a preliminary study

Çiğdem Coşkun Türer & Hanifi Ipek & Tuğrul Kirtiloğlu &

Gökhan Açikgöz

Received: 23 November 2012 /Accepted: 13 May 2013# Springer-Verlag London 2013

Abstract The aim of this clinical study was to compare dimen-sional changes of the transplanted grafts when the recipient areawas prepared with either erbium:yttrium, aluminum, and garnet(Er:YAG) laser or scalpel in free gingival grafts (FGGs). In thefirst and second groups of ten patients, the recipient area wasprepared with an Er:YAG laser and a scalpel, respectively. Allgrafts were harvested from the palate at standard dimensions(horizontal, 14 mm; vertical, 8 mm). Probing depth, clinicalattachment level, and keratinized tissue width were measuredbefore surgery. FGG dimensions (width, length, and area) weremeasured using the University of North Carolina-15 manualprobe (N15) (Nordent Manufacturing, Inc., IL, USA) duringsurgery and at 10, 21, and 90 days postoperatively. Differencesbetween the two groups were statistically analyzed. In bothgroups, there was a statistically significant reduction in verticaland horizontal dimensions (p<0.05) and graft area (p<0.05) atall time points compared to the baseline measurements. Therewere no significant differences between the two groups withrespect to vertical and horizontal dimensions and graft area atday 90 (p>0.05). The Er:YAG laser may be used with similareffectiveness as the scalpel in the preparation of the recipient sitefor free gingival grafts.

Keywords Free gingival graft . Er:YAG laser .

Graft dimension . Shrinkage

Introduction

The attached gingiva, which is covered by keratinized epitheli-um, is a dense, collagenous connective tissue firmly bound to theunderlying alveolar bone and root surface. Clinically, the at-tached gingiva is defined as the tissue between the mucogingivaljunction and the most apical portion of the gingival sulcus or theperiodontal pocket [1]. Several studies have suggested that aminimal amount of attached gingiva is essential for the mainte-nance of gingival health [2,3], which is in contrast to otherstudies that have demonstrated that good mechanical plaquecontrol can maintain gingival health, irrespective of the presenceor absence of the attached gingiva [4]. Because the role playedby the attached gingiva in the maintenance of gingival health is acontroversial subject, clinicians should be able to diagnose whatconstitutes a mucogingival problem [5]. It is shown that withlack of attached gingiva, the oral hygiene procedures are difficultto perform, resulting in plaque accumulation and inflammation[5,6]. Although it may be possible to maintain oral health withlittle or no attached gingiva, it is widely agreed that an attachedgingiva of less than 2 mm width poses a risk for gingivalrecession [7], so those areas should be carefully evaluated.

Mucogingival surgery is performed to increase theapicocoronal and buccolingual dimensions of gingival tis-sues as well as to halt or prevent recession, to facilitateplaque control, to improve esthetics, and to reduce or elim-inate root sensitivity [5]. Since Björn described the freegingival graft (FGG) procedure in 1963, it has been widelyused for gingival augmentation. Areas with a lack ofkeratinized tissue and gingival recession can be effectivelytreated with FGG techniques to create an adequate zone ofattached gingiva and coverage of the exposed root [1].

With the development of the ruby laser by Maiman in the1960s, lasers have become widely employed in medicineand surgery [8]. They are a viable alternative with different

Ç. C. Türer (*) : T. Kirtiloğlu :G. AçikgözDepartment of Periodontology, Faculty of Dentistry,Ondokuz Mayis University, 55139 Kurupelit,Samsun, Turkeye-mail: cigdemturer@gmail.com

H. IpekDepartment of Periodontology, Center for Oraland Dental Health, Eskisehir, Turkey

Lasers Med SciDOI 10.1007/s10103-013-1349-7

wavelengths to the scalpel for many intraoral, soft tissue,and surgical procedures. Procedures performed with carbondioxide (CO2) laser; potassium titanyl phosphate lasers(532 nm); gallium arsenide (diode) lasers (808–980 nm);neodymium:yttrium, aluminum, and garnet (Nd:YAG) lasers(1,064 nm); erbium, chromium-doped yttrium, scandium, gal-lium, and garnet lasers (2,780 nm); and erbium:yttrium, alu-minum, and garnet (Er:YAG) lasers (2,940 nm) include scal-ing and root planning, frenectomy, gingivectomy andgingivoplasty, desepithelization of reflected periodontal flaps,removal of granulation tissue, second-stage exposure of dentalimplants, lesion ablation, incisional and excisional biopsies ofboth benign and malignant lesions, irradiation of aphthousulcers, coagulation of free gingival donor sites, and gingivaldepigmentation [9–11].

Studies contrasting laser and scalpel surgery have dem-onstrated the advantages of the laser in coagulation thatresults in a dry surgical field and better visualization; tissuesurface sterilization; reduction in bacteremia; decreasedswelling, edema, and scarring; decreased pain; and greaterpatient acceptance [12,13]. Laser instruments, includingCO2, Nd:YAG, argon, diode, and Er:YAG, were found tobe effective in soft tissue surgery, including periodontology[14,15]. An Er:YAG laser device which was developed inthe early 1970s [16] was cleared for marketing by the USFood and Drug Administration in 1997 for certain hard andsoft tissue procedures, such as caries removal and cavitypreparation as well as incision and excision of intraoral softtissues [17]. Since then, the emphasis on the use of lasersonly on soft tissue has changed markedly.

Although some studies have evaluated the dimensionalchanges in free gingival grafts, to our knowledge, there havebeen no studies comparing dimensional changes in FGGs inwhich the recipient area was created with an instrumentother than a scalpel. We hypothesized that the Er:YAG laser,with its higher capacity for coagulation and sterilization ofthe affected tissues, may be an effective instrument forcreating the recipient area for the FGG.

Therefore, the aim of this clinical study was to comparethe dimensional changes of grafts during a period of 90 dayswhen the recipient area was prepared with either theEr:YAG laser or scalpel in FGGs.

Materials and methods

Study design and population

The study design was a randomized controlled trial, and thestudy population was selected from the patients of thePeriodontology Clinic of the Faculty of Dentistry, OndokuzMayis University, between December 2009 and January 2011.A total of 20 patients (11 females and 9 males) aged between

18 and 25 who needed an FGG operation over a standardizedmandibular incisor area were randomly divided into twogroups of ten patients (Fig. 1). Only systemically healthy,nonsmoking patients who were not taking medication andhad good oral hygiene were included. All patients received ageneral dental and periodontal examination and phase I peri-odontal therapy before the FGG; also, the same examinerperformed the operation with both techniques. Patients diag-nosed with periodontitis and patients with high plaque scoresafter phase I therapy were excluded from the study.

Surgical procedures

Anesthesia

Lidocaine HCl (20 mg/ml) containing 0.125 mg/ml epineph-rine solution (Jetocaine; Adeka Manufacturing, Samsun,Turkey) was used to anesthetize the palatal and recipient areas.To avoid edema in the surgical area, the local infiltration wasperformed distant from the recipient area.

Preparation of the recipient area in the laser group

An Er:YAG laser (Fotona AT Fidelis Plus III; Ljubljana,Slovenia) was used to prepare the recipient area for theFGG, using the 3-W, 300-mJ, 10-Hz, and very long pulse(1,000 μs) mode. Root surface modification was alsoperformed with the Er:YAG laser, using the 1.20-W, 120-mJ, 10-Hz, and medium short pulse (100 μs) mode (Fig. 2).A dental handpiece angled at 90° (R-14C) was used with acylindrical sapphire (1.3×12 mm) fiber optic tip both for themucosa and root surface. The desepithelization of the mu-cosa was created with a scanning movement. The tip wasdirected perpendicular to the tooth's long axis to avoidcontact with the enamel. Until graft placement, gauze moist-ened with saline solution was placed on the recipient bed.Due to the standardized palatal graft size of 14×8 mm, therecipient area was prepared 15 mm mesiodistally and slight-ly more than 8 mm apicocoronally to minimize the risk ofmovement of the FGG. For standardization of the recipient

Fig. 1 Preoperative view of recipient area. Note the reduced amount ofattached gingiva and gingival recession

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area, the University of North Carolina-15 manual probe (N15)(Nordent Manufacturing, Inc., IL, USA) was used to deter-mine the four grid points to create the corners of a rectanglearea. During surgery, patients and the surgical team worespecial laser eyeglasses to prevent injury.

Preparation of the recipient area in the scalpel group

As in the laser group, due to the standardized palatal graftsize of 14×8 mm, a 15-mm horizontal incision was mademesiodistally along the mucogingival junction, and twovertical incisions of slightly more than 8 mm were madefrom the cut gingival margin to the alveolar mucosa. A splitthickness flap was separated without disturbing the perios-teum at the recipient site. For standardization of the recipientarea, the University of North Carolina-15 manual probe(N15) (Nordent Manufacturing, Inc., IL, USA) was used todetermine the four grid points to create the corners of arectangle area.

Harvesting the graft

After preparing the recipient area, the palatal graft washarvested using a number 15 scalpel (Beybi Manufacturing,Istanbul, Turkey) between the distal edge of the canine and thefirst molar, at 2 mm away from the gingival margin. Thehorizontal and vertical dimensions of the grafts were 14 and8 mm, respectively, and their thickness was approximately 1.0–1.5 mm (Fig. 3). The graft thickness was calculated with thesame periodontal probe by inserting the probe perpendicularlyinto the donor region; if necessary, the graft was prepared(thinned) to obtain a graft approximately 1 to 1.5 mm thick.All dimensions were measured using the University of NorthCarolina-15manual probe (N15) (NordentManufacturing, Inc.,IL, USA). After excision of the graft, gauze moistened withsaline was applied to the donor area to achieve hemostasis, andthe harvested graft was immediately placed in the recipient area.

Placement of the graft

The graft was sutured with 5–0 silk sutures (Dogsan,Trabzon, Turkey); one suture was inserted on both the distaland mesial edges, and a suspensory recipient suture wasused for graft stabilization, without penetrating the graft.The graft was firmly held in place using digital pressurefor 5 min with gauze moistened with saline.

Postsurgical care

Patients were instructed to rinse with 0.12 % chlorhexidinegluconate (Oroheks Plus, Tripharma, Turkey) three timesdaily for 21 days. To minimize the risk of postoperativeinfection, patients were also prescribed with the antibioticamoxicillin/clavulanic acid 500/125 mg twice daily for 7 daysafter surgery. Sutures were removed 10 days after surgery. Thesame examiner measured the length and width of the graftusing the University of North Carolina-15 manual probe(N15) (Nordent Manufacturing, Inc., IL, USA) at 10, 21,

Fig. 2 Prepared recipient area for FGG when using Er:YAG laser

Fig. 3 Graft harvested from the palatal donor area with dimensions of14×8 mm

Fig. 4 At 90 days, the postoperative view of the transplanted graftwhen using Er:YAG laser

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and 90 days postoperatively, and the graft area was calculatedby multiplying its length and width.

Statistical analysis

The group subjected to the standard scalpel technique wastaken as the control group. Data were expressed as means ±standard deviation or frequency of the parameters evaluated.The statistical analysis was performed using a commerciallyavailable software program (SPSS 16.0; SPSS, Inc., Chicago,IL, USA). Normality of distribution was tested with theShapiro–Wilk procedure. The Student's t test was used forthe intergroup comparisons, and analysis of variance was usedfor intragroup comparisons. The statistical significance levelwas set at p<0.05.

Results

The grafts of all patients healed without complications(Fig. 4). Regular controls were done weekly for stabilizingthe plaque index (PI) score under 20 %. In the laser group,

the PI was 18±2.1 and 15±4.7 % at the beginning of thestudy and 90 days postoperatively, respectively, and in thecontrol group, it was 17±2.7 and 16±2.5 % at the beginningand 90 days postoperatively, respectively.

At 90 days postoperatively, the FGG width, length, andarea were reduced by 15.87, 24.3, and 32.67 %, respectively,in the control group, and by 16.42, 22.5, and 35.22 % in thelaser group. The horizontal and vertical dimensional changesof the FGGs are detailed in Tables 1 and 2, and changes in thegrafted areas are detailed in Table 3.

Intragroup comparisons in both the laser and controlgroups revealed significant reductions in vertical and hori-zontal dimensions (p<0.01) and in graft area (p<0.05) at allvisits. However, there were no significant differences be-tween the two groups for the vertical and horizontal dimen-sions and graft area at day 90 (p>0.05).

Discussion

The present study compared the dimensional changes of FFGsin recipient areas prepared with an Er:YAG laser or scalpel.

Table 1 The horizontal graftdimensions in the laser andscalpel (control) groups(mean ± SD)

*p>0.05, no difference betweengroups at all visits (intergroup);**p<0.01, significantly differentat all visits (intragroup)

Horizontal dimensions (mm) Laser group (n=10) Control group (n=10) p*

Baseline 14 14

10 days 12.95±0.28 13.11±0.22 >0.05

21 days 12.65±0.52 12.00±0.50 >0.05

90 days 11.70±0.78 11.77±0.44 >0.05

p** <0.01 <0.01

Table 2 The vertical graft di-mensions in the laser and scalpel(control) groups (mean ± SD)

*p>0.05, no difference wasfound between groups in allvisits (intergroup); **p<0.01,significantly different in all visits(intragroup)

Vertical dimensions (mm) Laser group (n=10) Control group (n=10) p*

Baseline 8 8

10 days 7.30±0.42 7,16±0.35 >0.05

21 days 6.35±1.00 6,44±0.39 >0.05

90 days 6.20±0.78 6,05±0.16 >0.05

p** <0.01 <0.01

Table 3 The graft area in thelaser and scalpel (control)groups (mean ± SD)

*p>0.05, no difference betweengroups at all visits (intergroup);**p<0.05, significantly differentat all visits (intragroup)

Area (mm2) Laser group (n=10) Control group (n=10) p*

Baseline 112 112

10 days 94.55±6.15 93.94±4.44 >0.05

21 days 80.37±13.75 77.38±6.39 >0.05

90 days 72.55±10.56 71.33±3.60 >0.05

p** <0.05 <0.05

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Although there have been studies in which the recipient areawas prepared with various lasers, to our knowledge, no earlierpublication has reported a comparison of the dimensionalchanges in free gingival grafts when the recipient area wasprepared with either a scalpel or Er:YAG laser.

Advantages that include surface sterilization, good he-mostasis, reduced bleeding intraoperatively, patient comfort,and less postoperative pain mean that lasers are widelyemployed in gingival surgery in periodontology. Many stud-ies have evaluated the advantages and disadvantages of CO2

and Nd:YAG lasers in intraoral soft tissue procedures [9].However, their negative effects when used directly on boneand root surfaces have been elicited in many studies andinclude carbonization and thermal damage to the underlyingbone [18–20]; other studies have shown that the Er:YAGlaser is the most appropriate one for use directly on hardtissue for minimization of thermal damage and creation of asurface that enhances compatibility and soft tissue attach-ment [21,22]. Studies have also demonstrated that theEr:YAG laser has a considerable ability to remove lipopoly-saccharides from root surfaces and also to facilitate removalof the smear layer after root planning [21–23]. In our study,the Er:YAG laser was chosen because it can be used both onsoft tissue for partial thickness flap design and on hard tissuefor root surface modification.

FGG is a mucogingival periodontal surgery which isperformed for gingival augmentation [1]. Graft shrinkagethat occurs during the healing process is a well-knownclinical phenomenon [24]. Vertical shrinkage occurs througha contraction of the wound and by reinsertion of the musclefibers [25]. Horizontal shrinkage is also an important clini-cal consideration in mucogingival surgery [26,27].

Previous studies in which the recipient bed was preparedwith a scalpel showed that shrinkage occurs after grafttransplantation [26–29]. Mörmann et al. reported mean ver-tical graft shrinkage of 42.3 % at 12 months [28], and Orsiniet al. reported mean vertical graft shrinkages of 10.2, 28.4,37.2, and 43.25 % at 1-, 4-, 26-, and 52-week follow-ups,respectively [29]. In another study, Hatipoğlu et al. evaluat-ed the shrinkage of FGGs in two dimensions and reportedhorizontal and vertical shrinkages of 10.2 and 32.1 %, re-spectively, in a case report series on a 180-day study [26].

Thickness of the graft may be related to vascularization,healing period, and graft dimensions. Microscopically,healing of a graft of intermediate thickness (0.75 mm) isnormally complete at 10.5 weeks, although thicker grafts(1.75 mm) may require 16 weeks or longer [30]. Sullivanand Atkins reported that if the procedure is to be performedcorrectly, a graft thickness of 1–2 mm is crucial for thesuccessful coverage of denuded roots [31]. In another study,Maynard reported that a graft thickness of about 0.9 mm onthe periosteal bed was sufficient for the proper functioning ofthe new tissue; but optimal thickness of the transplanted tissue

was reported as 1–1.5 mm [32]. While there have been differ-ent minimal thicknesses reported for successful grafting, in thepresent study, all grafts were standardized to 1–1.5 mm.

Visser et al. reported that the CO2 laser is useful for theFGG procedure because of its good ability to achieve hemo-stasis and low mechanical stress on the recipient bed, withouthindering attachment or wound healing of the delicate freegingival graft [33]. Finkbeiner reported that the argon laser isalso useful for making incisions for gingival grafts [34].

While previous studies have consistently reported that themajor dimensional changes of the graft are occurring until3 months, the present study was concluded at 90 days[35,36]. In fact, studies did not report significant dimension-al changes after the first 21 and 30 days of healing period[26,27,37].

In the present clinical study, the grafts healed without anycomplications in both groups. The study also showed thatthere were no significant differences between the laser andscalpel groups with respect to vertical and horizontal di-mensions and graft area at day 90 (p>0.05).

In conclusion, the Er:YAG laser may be used with thesame effectiveness as the scalpel for recipient area prepara-tion in free gingival grafting.

Acknowledgments The authors thank Gregory T. Sullivan of theSchool of Foreign Languages at the Ondokuz Mayis University inSamsun, Turkey, for his proofreading.

Conflict of interest The authors report no conflict of interest relatedto this study.

References

1. Orban B (1948) Clinical and histologic study of the surface char-acteristics of the gingiva. Oral Surgery 1:827–841

2. Gartrell JR, Mathews DP (1976) Gingival recession, the condition,process and treatment. Dent Clin N Am 20:199–213

3. Schmid MO (1976) The subperiosteal vestibule extension. Literaturereview, rationale and technique. J West Soc Periodontol 24:89–99

4. Wennström J, Lindhe J (1983) Role of attached gingiva for main-tenance of periodontal health. Healing following excisional andgrafting procedures in dogs. J Clin Periodontol 10:206–221

5. Camargo PM, Melnick PR (2000) Kenney EB (2001) The use offree gingival grafts for aesthetic purposes. Periodontol 27:72–96

6. Müller HP, Eger T, Schorb A (1998) Gingival dimensions afterroot coverage with free connective tissue grafts. J Clin Periodontol25:424–430

7. Lang NP, Löe H (1972) The relationship between the width ofkeratinized gingiva and gingival health. J Periodontol 43:623–627

8. Rossmann JA (2002) Lasers in periodontics. A position paper bythe American Academy of Periodontology. J Periodontol 73:1231–1239

9. Cobb CM (2006) Lasers in periodontics: a review of the literature.J Periodontol 77:545–564

10. Romeo U, Palaia G, Del Vecchio A, Tenore G, Gambarini G,Gutknecht N, De Luca M (2010) Effects of KTP laser on oral softtissues. An in vitro study. Lasers Med Sci 25(4):539–543

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11. Badran Z, Boutigny H, Struillou X, Weiss P, Laboux O, SoueidanA (2012) Clinical outcomes after nonsurgical periodontal therapywith an Er:YAG laser device: a randomized controlled pilot study.Photomed Laser Surg 30(7):347–353

12. Wigdor H, Walsh J, Featherstone JDB et al (1995) Lasers indentistry. Lasers Surg Med 16:103–133

13. Bader H (2000) Use of lasers in periodontics. Dent Clin N Am44:779–792

14. Israel M (1994) Use of the CO2 laser in soft tissue and periodontalsurgery. Pract Periodontics Aesthet Dent 6(6):57–64

15. Romanos GE (1994) Clinical applications of the Nd:YAG laser inoral soft tissue surgery and periodontology. J Clin Laser Med Surg12(2):103–108

16. Zharikov EV, Zhekov VI, Kulevskii LA, Murina TM, Osiko VV,Prokhorov AM, Savel'ev AD, Smirnov VV, Starikov BP,Timoshechkin MI (1975) Stimulated emission from Er3+ ionsinyttrium aluminum garnet crystal at L=2.94 μ. Sov J QuantumElectron 4(8):1039–1040

17. Stojan T (2010) 5. 510(k) Summary. http://www.accessdata.fda.gov/cdrh_docs/pdf10/K101817.pdf. Accessed 23 Nov 2012

18. Spencer P, Cobb CM, Wieliczka DM, Glaros AG, Morris PJ(1998) Change in temperature of subjacent bone during soft tissuelaser ablation. J Periodontol 69:1278–1282

19. Williams TM, Cobb CM, Rapley JW, Killoy WJ (1995) Histologicevaluation of alveolar bone following CO2 laser removal of con-nective tissue from periodontal defects. Int J Periodontics RestorDent 15:497–506

20. Krause LS, Cobb CM, Rapley JW, Killoy WJ (1997) Laser irradi-ation of bone: an in vitro study concerning the effects of the CO2

laser on oral mucosa and subjacent bone. J Periodontol 68:872–880

21. Yamaguchi H, Kobayashi K, Reiko O et al (1997) Effects ofirradiation of an erbium:YAG laser on root surfaces. JPeriodontol 68:1151–1155

22. Israel M, Cobb CM, Rossmann JA, Spencer P (1997) The effectsof the CO2, Nd:YAG and Er:YAG lasers with and without surfacecoolant on the tooth root surfaces: an in vitro study. J ClinPeriodontol 24:595–602

23. Aoki A, Ando Y, Watanebe H, Ishikawa I (1994) In vitro studieson laser scaling of subgingival calculus with an erbium:YAG laser.J Periodontol 65:1097–1106

24. Pennel BM, Tabor JC, King KO, Towner JD, Fritz BD, HiggasonJD (1969) Free masticatory mucosa graft. J Periodontol 40:162–166

25. Donoff RB (1976) Biological basis for vestibuloplasty procedures.J Oral Surg 34:890–896

26. Hatipoğlu H, Keçeli HG, Güncü GN, Şengün D, Tözüm TF (2007)Vertical and horizontal dimensional evaluation of free gingivalgrafts in the anterior mandible: a case report series. Clin OralInvest 11:107–113

27. Silva CO, Ribeiro EP, Sallum AW, Tatakis DN (2010) Free gingi-val grafts: graft shrinkage and donor-site healing in smokers andnon-smokers. J Periodontol 81:692–701

28. Mörmann W, Schaer F, Firestone AR (1981) The relationshipbetween success of free gingival grafts and transplant thickness.Revascularization and shrinkage—a one year clinical study. JPeriodontol 52:74–80

29. Orsini M, Orsini G, Benlloch D, Aranda JJ, Lazaro P, Sanz M(2004) Esthetic and dimensional evaluation of free connectivetissue grafts in prosthetically treated patients: a 1-year clinicalstudy. J Periodontol 75:470–477

30. Gordon HP, Sullivan HC, Atkins JH (1968) Free autogenousgingival grafts. II. Supplemental findings: histology of the graftsite. Periodontics 6:130–133

31. Sullivan HC, Atkins JH (1968) Free autogenous gingival grafts.III. Utilization of grafts in the treatment of gingival recession.Periodontics 6:152–160

32. Maynard JG (1977) Coronally positioning of a previously placedautogenous gingival graft. J Periodontol 48:151–155

33. Visser H, Mausberg R (1996) Free gingival grafts using a CO2

laser: results of a clinical study. J Clin Laser Med Surg 14:85–8834. Finkbeiner RL (1995) Free autogenous soft tissue graft with the

argon laser. J Clin Laser Med Surg 13:1–535. James WC, McFall WT Jr (1978) Placement of free gingival grafts

on denuded alveolar bone. Part I: clinical evaluations. JPeriodontol 49:283–290

36. Dreeskamp M, de Jacoby LF (1973) Breadth of the gingiva propriain vestibuloplasty following gingiva transplantation (in German).Dtsch Zahnarztl Z 28:192–197

37. Barbosa FI, Corrêa DS, Zenóbio EG, Costa FO, Shibli JA (2009)Dimensional changes between free gingival grafts fixed with ethylcyanoacrylate and silk sutures. J Int Acad Periodontol 11:170–176

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