Oral and Maxillofacial Surgery

, Volume 22, Issue 2, pp 215–223 | Cite as

Comparative evaluation of soft and hard tissue changes following endosseous implant placement using flap and flapless techniques in the posterior edentulous areas of the mandible—a randomized controlled trial

  • Divya Kumar
  • G Sivaram
  • B Shivakumar
  • TSS Kumar
Original Article



Dental implant-supported restorations have long been used as a successful modality for replacing missing teeth. There are two well-established methods of implant placement. The traditional approach to implant surgery involves raising a mucoperiosteal flap and the alternative approach does not involve reflecting a flap, each having its own advantages and disadvantages. The purpose of the present study was to compare and evaluate the soft and hard tissue changes around endosseous implants placed using flap and flapless surgery in mandibular posterior edentulous sites over a period of time.

Materials and methods

A total of 20 systemically healthy patients with a single edentulous site in the posterior mandible were enrolled in this study and 20 endosseous implants were placed (10 in the flap group and 10 in the flapless group). The peri-implant probing depth was assessed. Radiographic assessment was done for changes in the marginal bone levels at the mesial and distal side of the implant with measurements made at baseline, 6 months, and 12 months. Patient-centered outcomes were assessed by using the visual analogue scale (VAS). All these parameters were statistically analyzed using the Wilcoxon signed-rank test, paired Student t test, and two-way ANOVA test and were considered to be significant if the p value was ≤ 0.05.


Twenty patients were enrolled in the present study and endosseous implants were placed. Eighteen subjects were followed up throughout the study period and two patients were excluded from the study. The mean PD in the flapless group was comparatively less than the flap group at 12 months and was found to be statistically significant. During the observation period of 12 months, reduction of crestal bone height around the implants placed by flapless and flap surgery were statistically significant. The flapless group showed less change in the crestal bone height which was statistically significant compared to the flap group. The mean VAS score on day 0 in the flap and flapless group was statistically significant. The flapless group showed significantly less pain when compared to the flap group.


Although the flapless technique of endosseous implant placement had statistically significant less PD, bone loss, and pain than the flap technique, the difference was found to have uncertain clinical significance.


Endosseous implants Flap and flapless method Peri-implant probing Crestal bone loss 



bone implant contact


visual analogue scale


probing depth


keratinized mucosa


crestal bone height


Wilcoxon signed-rank test


cumulative success rate


Authors’ contributions

Dr.Divya Kumar (DK): Has performed the clinical trial and has significantly played a role in the acquisition of data, interpretation and drafting the manuscript.

Dr.Sivaram Gopalakrishnan (SG): Has made substantial contributions to conception and design of the study, guided the clinical procedures and critical evaluation of the manuscript and its revision.

Dr.Shivakumar Baskaran (SB): Has contributed to the study design and co-ordinated the clinical procedures.

Dr.T.S.S.Kumar (TSSK): Has mentored the study, revised the manuscript, and has given the final approval of the version to be published.

All the authors have read and approved the final manuscript.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.

Ethics approval

The study was approved by the Institutional Review Board prior to commencement. All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.

Informed consent

Informed consent was obtained from all individual participants included in the study.


  1. 1.
    Abrahamsson I, Berglundh T, Wennströmm J, Lindhe J (1996) The periimplant hard and soft tissue characteristics at different implant systems. A comparative study in the dog. Clin Oral Implants Res 7:212–219CrossRefPubMedGoogle Scholar
  2. 2.
    Adell R, Eriksson B, Lekholm U, Branemark PI, Jemt T (1990) Long-term follow-up study of osseointegrated implants in the treatment of totally edentulous jaws. Int J Oral Maxillofac Implants 5:347–359PubMedGoogle Scholar
  3. 3.
    Adell R, Lekholm U, Rockler B, Branemark PI. A 15-year study of osseointegrated implants in the treatment of the edentulous jaw. Int J Oral Surg1981; 10:387–416Google Scholar
  4. 4.
    Aires I, Berger J (2002) Simultaneous immediate placement and immediate loading of implants in the maxilla: a case presentation. J Calif Dent Assoc 30:227–232PubMedGoogle Scholar
  5. 5.
    Akagawa Y, Takata T, Matsumoto T (1989) Correlation between clinical and histological evaluations of the peri-implant gingiva around the single-crystal sapphire endosseous implant. J Oral Rehabil 16(6):581–587CrossRefPubMedGoogle Scholar
  6. 6.
    Al-Ansari BH, Morris RR (1998) Placement of dental implants without flap surgery. A clinical report. Int J Oral Maxillofac Implants 13:861–865PubMedGoogle Scholar
  7. 7.
    Al-Khabbaz AK, Griffin TJ, Al-Shammari KF (2007) Assessment of pain associated with the surgical placement of dental implants. J Periodontol 78:239–246CrossRefPubMedGoogle Scholar
  8. 8.
    Arisan V, Karabuda CZ, Ozdemir T (2010) Implant surgery using bone- and mucosa-supported stereolithographic guides in totally edentulous jaws: surgical and post-operative outcomes of computer-aided vs. standard techniques. Clin Oral Implants Res 21:980–988CrossRefPubMedGoogle Scholar
  9. 9.
    Becker W, Becker BE, Alsuwyed A, Al-Mubarak S. Long-term evaluation of 282 implants in maxillary and mandibular molar positions: a prospective study. J Periodontol 1999 Aug 1;70(8):896–901Google Scholar
  10. 10.
    Becker W, Goldstein M, Becker BE, Sennerby L, Kois D, Hujoel P (2005) Minimally invasive flapless implant surgery: a prospective multicenter study. Clin Implant Dent Relat Res 7(suppl 1):S21–S27CrossRefPubMedGoogle Scholar
  11. 11.
    Berglundh T, Abrahamsson I, Welander M, Lang NP, Lindhe J (2007) Morphogenesis of the peri-implant mucosa: an experimental study in dogs. Clin Oral Implants Res 18:1–8CrossRefPubMedGoogle Scholar
  12. 12.
    Campelo LD, Camara JR (2002) Flapless implant surgery: a 10-year clinical retrospective analysis. Int J Oral Maxillofac Implants 17(2):271–276PubMedGoogle Scholar
  13. 13.
    Carmichael R, Apse P, Zarb G, Biological MCC (1989) Microbiological and clinical aspects of the pre-implant mucosa. In: Albrektsson T, Zarb G (eds) The bra°nemark Osseointergrated implant. Chicago: quintessence, pp 39–78Google Scholar
  14. 14.
    Casap N, Tarazi E, Wexler A, Sonnefield U (2005) Intraoperative computerized navigation for flapless implant surgery and immediate loading in edentulous mandible. Int J Oral Maxillofac Implants 20:92–98PubMedGoogle Scholar
  15. 15.
    Chrcanovic BR, Albrektsson T, Wennerberg A (2014) Flapless versus conventional flapped dental implant surgery: a meta-analysis. PLoS One 9(6):e100624CrossRefPubMedPubMedCentralGoogle Scholar
  16. 16.
    De Bruyn H, Atashkadeh M, Cosyn J, van de Velde T (2011) Clinical outcome and bone preservation of single TiUnite™ implants installed with flapless or flap surgery. Clin Implant Dent Relat Res 13:175–183CrossRefPubMedGoogle Scholar
  17. 17.
    Ekelund JA, Lindquist LW, Carlsson GE, Jemt T (2003) Implant treatment in the edentulous mandible: a prospective study on Branemark system implants over more than 20 years. Int J Prosthodont 16:602–608PubMedGoogle Scholar
  18. 18.
    Esposito M, Worthington HV, Coulthard P (2003) Interventions for replacing missing teeth: different times for loading dental implants. Cochrane Database Syst Rev 1:CD003878Google Scholar
  19. 19.
    Fortin T, Bosson JL, Isidori M, Blanchet E (2006) Effect of flapless surgery on pain experienced in implant placement using an image guided system. Int J Oral Maxillofac Implants 21:298–304PubMedGoogle Scholar
  20. 20.
    Gotfredsen K, Berglundh T, Lindhe J (2001) Bone reactions to titanium implants with different surface characteristics subjected to static load. A study in the dog (II). Clin Oral Implants Res 12:196–201CrossRefPubMedGoogle Scholar
  21. 21.
    Hoshaw SJ, Brunski JB, Cochran GVB (1994) Mechanical loading of Branemark implants affects interfacial modeling and remodeling. Int J Oral Maxillofac Implants 9:345–360Google Scholar
  22. 22.
    Hruska A, Borelli P, Bordanaro AC, Marzaduri E, Hruska KL (2002) Immediate loading implants: a clinical report of 1301 implants. J Oral Implantol 28:200–209CrossRefPubMedGoogle Scholar
  23. 23.
    Iyer S, Weiss C, Mehta A (1997) Effects of drill speed on heat production and the rate and quality of bone formation in dental implant osteotomies. Part I: relationship between drill speed and heat production. Int J Prosthodont 10:411–414PubMedGoogle Scholar
  24. 24.
    Kawahara H., Kawahara D., Hashimoto K., Takashima Y., Ong J. L. 1998. Morphologic studies on the biologic seal of titanium dental implants. Report I. In vitro study on the epithelialization mechanism around the dental implant. Int. J. Oral Maxillofac. Implants 13, 457–464Google Scholar
  25. 25.
    Kinsel RP, Lamb RE (2000) Development of gingival esthetics in the edentulous patient with immediately loaded, single stage, implant supported fixed prosthesis : a clinical report. Int J Oral Maxillofac Implants 15:711–721PubMedGoogle Scholar
  26. 26.
    Laney WR, Jemt T, Harris D, Henry PJ, Krogh PH, Polizzi, G, and others. Osseointegrated implants for single-tooth replacement: progress report from a multicenter prospective study after 3 years. Int J Oral Maxillofac Implants 1994; 9:49–54Google Scholar
  27. 27.
    Lekholm U, Gunne J, Henry P, Higuchi K, Linden U, Bergstrom C, and other. Survival of the Branemark implant in partially edentulous jaws: a 10-year prospective multicenter study. Int J Oral Maxillofac Implants 1999; 14:639–645Google Scholar
  28. 28.
    Lin GH, Chan HL, Bashutski JD, Oh TJ, Wang HL (2014) The effect of flapless surgery on implant survival and marginal bone level: a systematic review and meta-analysis. J Periodontol 85:e91–e103Google Scholar
  29. 29.
    Lorenzoni M, Pertl C, Zhang K, Wimmer G, Wegscheider WA (2003) Immediate loading of single tooth implants in the anterior maxilla. Preliminary results after one year. Clin Oral Implants Res 14:180–187CrossRefPubMedGoogle Scholar
  30. 30.
    McKinney R, James RA: Tissues surrounding dental implants. In Misch CE, Contemporary implant dentistry, St Louis, Mosby 1993:369–386Google Scholar
  31. 31.
    Misch CE, Bidez MW, Sharawy M. A bioengineered implant for a predetermined bone cellular response to loading forces. A literature review. J Periodontol 2001; 72: 1276–1286Google Scholar
  32. 32.
    Mombelli A, Lang NP (1994) Clinical parameters for evaluation of dental implants. Periodontol 2000 4:81–86CrossRefPubMedGoogle Scholar
  33. 33.
    Nkenke E, Eitner S, Radespiel-Tröger M, Vairaktaris E, Neukam FW, Fenner M (2007) Patient-centred outcomes comparing transmucosal implant placement with an open approach in the maxilla: a prospective, non-randomized pilot study. Clin Oral Implants Res 18:197–203CrossRefPubMedGoogle Scholar
  34. 34.
    Ozan O, Turkyilmaz I, Yilmaz B (2007) A preliminary report of patients treated with early loaded implants using computerized tomography-guided surgical stents: flapless versus conventional flapped surgery. J Oral Rehabil 34:835–840CrossRefPubMedGoogle Scholar
  35. 35.
    Pontoriero R, Tonelli MP, Carnevale G, Mombelli A, Nyman SR, Lang NP, (1994) Experimentally induced peri-implant mucositis. A clinical study in humans. Clin Oral Implants Res 5(4):254–259CrossRefPubMedGoogle Scholar
  36. 36.
    Ramfjord SP, Costich ER (1968) Healing after exposure of periosteum on the alveolar process. J Periodontol 38:199–207CrossRefGoogle Scholar
  37. 37.
    Rocci A, Martignoni M, Gottlow J (2003) Immediate loading in the maxilla using flapless surgery, implants placed in predetermined positions, and prefabricated provisional restorations: a restrospective 3-year clinical study. Clin Implant Dent Relat Res 5(suppl 1):29–36CrossRefPubMedGoogle Scholar
  38. 38.
    Seymour R, Charlton J, Phillips M (1983) An evaluation of dental pain using visual analogue scales and the McGill pain questionnaire. J Oral Maxillofac Surg 41:643–648CrossRefPubMedGoogle Scholar
  39. 39.
    Strub JR, Gaberthuel TW, Grunder U (1991) The role of attached gingiva in the health of peri-implant tissue in dogs, clinical findings. Int J Periodontics Restorative Dent 11:317–333PubMedGoogle Scholar
  40. 40.
    Sunitha RV, Sapthagiri E (2013) Flapless implant surgery: a 2-year follow-up study of 40 implants. Oral Surg Oral Med Oral Pathol Oral Radiol 116:e237–e243CrossRefGoogle Scholar
  41. 41.
    Tonetti MS, Schmid J (1994) Pathogenesis of implant failures. Periodontol 2000 4(1):127–138CrossRefPubMedGoogle Scholar
  42. 42.
    Tsoukaki M, Kalpidis CDR, Sakellari D, Tsalikis L, Mikrogiorgis G, Konstantinidis A. Clinical, radiographic, microbiological and immunological outcomes of flapped vs. flapless dental implants: a prospective randomized controlled clinical trial. Clin.Oral Impl. Res 2013 Sep;24(9):969–976Google Scholar
  43. 43.
    Van Steenberghe DA (1989) Retrospective multicenter evaluation of the survival rate of osseointegrated fixtures supporting fixed partial edentulism. J Prosthet Dent 61:217–223CrossRefPubMedGoogle Scholar
  44. 44.
    Vohra F, Al-Kheraif AA, Almas K, Javed F (2015) Comparison of crestal bone loss around dental implants placed in healed sites using flapped and flapless techniques: a systematic review. J Periodontol 86(2):185–191CrossRefPubMedGoogle Scholar
  45. 45.
    Warrer K, Buser D, Lang NP, Karring T (1995) Plaque-induced peri-implantitis in the presence or absence of keratinized mucosa. An experimental study in monkeys. Clin Oral Implants Res 6:131–138CrossRefPubMedGoogle Scholar
  46. 46.
    Wiskott HWA, Belser UC (1999) Lack of integration of smooth titanium surfaces: a working hypothesis based on strains generated in the surrounding bone. Clin Oral Implants Res 10:429–444CrossRefPubMedGoogle Scholar
  47. 47.
    Wood DL, Hoag PM, Donnenfeld OW, Rosenfeld LD (1972) Alveolar crest reduction following full and partial thickness flaps. J Periodontol 42:141–144CrossRefGoogle Scholar
  48. 48.
    Yeung SC (2008) Biological basis for soft tissue management in implant dentistry. Aust Dent J 53(Suppl. 1):S39–S42CrossRefPubMedGoogle Scholar
  49. 49.
    You TM, Choi BH, Li J, Xuan F, Jeong SM, Jang SO (2009 Jan) Morphogenesis of the peri-implant mucosa : a comparison between flap and flapless procedures in the canine mandible. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 107(1):66–70CrossRefPubMedGoogle Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Department of PeriodonticsRagas Dental College and HospitalChennaiIndia

Personalised recommendations